From 6aafeef03b9d9ecf255f3a80ed85ee070260e1ae Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Wed, 6 Nov 2013 17:52:20 +0100 Subject: netfilter: push reasm skb through instead of original frag skbs Pushing original fragments through causes several problems. For example for matching, frags may not be matched correctly. Take following example: On HOSTA do: ip6tables -I INPUT -p icmpv6 -j DROP ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT and on HOSTB you do: ping6 HOSTA -s2000 (MTU is 1500) Incoming echo requests will be filtered out on HOSTA. This issue does not occur with smaller packets than MTU (where fragmentation does not happen) As was discussed previously, the only correct solution seems to be to use reassembled skb instead of separete frags. Doing this has positive side effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams dances in ipvs and conntrack can be removed. Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c entirely and use code in net/ipv6/reassembly.c instead. Signed-off-by: Jiri Pirko Acked-by: Julian Anastasov Signed-off-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 56 +------------------------- 1 file changed, 2 insertions(+), 54 deletions(-) (limited to 'net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c') diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c index 486545eb42ce..4cbc6b290dd5 100644 --- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -169,64 +169,13 @@ out: return nf_conntrack_confirm(skb); } -static unsigned int __ipv6_conntrack_in(struct net *net, - unsigned int hooknum, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - struct sk_buff *reasm = skb->nfct_reasm; - const struct nf_conn_help *help; - struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - - /* This packet is fragmented and has reassembled packet. */ - if (reasm) { - /* Reassembled packet isn't parsed yet ? */ - if (!reasm->nfct) { - unsigned int ret; - - ret = nf_conntrack_in(net, PF_INET6, hooknum, reasm); - if (ret != NF_ACCEPT) - return ret; - } - - /* Conntrack helpers need the entire reassembled packet in the - * POST_ROUTING hook. In case of unconfirmed connections NAT - * might reassign a helper, so the entire packet is also - * required. - */ - ct = nf_ct_get(reasm, &ctinfo); - if (ct != NULL && !nf_ct_is_untracked(ct)) { - help = nfct_help(ct); - if ((help && help->helper) || !nf_ct_is_confirmed(ct)) { - nf_conntrack_get_reasm(reasm); - NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, reasm, - (struct net_device *)in, - (struct net_device *)out, - okfn, NF_IP6_PRI_CONNTRACK + 1); - return NF_DROP_ERR(-ECANCELED); - } - } - - nf_conntrack_get(reasm->nfct); - skb->nfct = reasm->nfct; - skb->nfctinfo = reasm->nfctinfo; - return NF_ACCEPT; - } - - return nf_conntrack_in(net, PF_INET6, hooknum, skb); -} - static unsigned int ipv6_conntrack_in(const struct nf_hook_ops *ops, struct sk_buff *skb, const struct net_device *in, const struct net_device *out, int (*okfn)(struct sk_buff *)) { - return __ipv6_conntrack_in(dev_net(in), ops->hooknum, skb, in, out, - okfn); + return nf_conntrack_in(dev_net(in), PF_INET6, ops->hooknum, skb); } static unsigned int ipv6_conntrack_local(const struct nf_hook_ops *ops, @@ -240,8 +189,7 @@ static unsigned int ipv6_conntrack_local(const struct nf_hook_ops *ops, net_notice_ratelimited("ipv6_conntrack_local: packet too short\n"); return NF_ACCEPT; } - return __ipv6_conntrack_in(dev_net(out), ops->hooknum, skb, in, out, - okfn); + return nf_conntrack_in(dev_net(out), PF_INET6, ops->hooknum, skb); } static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = { -- cgit